Charlie Duke on Apollo 11: 'I thought we'd have to abort'
Charlie Duke is one of only 12 men to have walked on the Moon - but two years before he and John Young got to explore the lunar surface during the Apollo 16 mission, Duke played a major part in the first moon landing.
As Mission Control's Cap Com, he was the only person allowed to speak directly to the Apollo 11 astronauts as Neil Armstrong and Buzz Aldrin touched down.
He told the BBC's Paul Rincon how he thought the landing would have to be aborted, and why he did not realise it was such a historic moment until afterwards.